<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
        "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
    <title>jQuery基本选择器</title>
    <meta charset="utf-8">
  
    <style type="text/css">
        div{
            background: gray;
            width: 200px;
            height: 100px;
        }
    </style>
</head>
<body>
    <!--定义被选择对象-->
    <div id="one" class="two"></div><br>
    <div class="two"></div><br>
    <div></div><br>
    <span>我是span标签</span>
    <br>
    <!--定义按钮-->
    <input type="button" id="btn01" value="选择id为one的元素"/>
    <input type="button" id="btn02" value="选择class为two的元素"/>
    <input type="button" id="btn03" value="选择所有div元素"/>
    <input type="button" id="btn04" value="选择所有元素"/>
    <input type="button" id="btn05" value="选择id为one与所有span元素"/>
</body>
</html>